DESCRIPTION The ethyl acetate (EtOAc) extracts of three tropical fruits, Garcinia xanthochymus (Guttiferae), Mammea americana (Guttiferae) and Threobroma grandiflorum (Sterculia, displayed antioxidant activity in the americana (Guttiferae) and Theobroma grandiflorum (Sterculiaceae), displayed antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The antioxidant constituents of these extracts activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The antioxidant constituents of these extracts have not been determined. In the proposed research, the three plants will be recollected from southern Florida., extracted with methanol, and separated using bioactivity (DPPH) guided reversed-phase high performance liquid chromatography-mass spectroscopy-mass spectroscopy. Isolated phytochemicals will be analyzed for their ability to prevent LDL-oxidation in vitro using a headscape GC bioassay. It is expected that this research will isolate known and novel antioxidants which inhibit LDL-oxidation in vitro. These compounds may serve as models for potential new therapeutic agents for the treatment of hypercholesterolemia.